Development of protection and control system complying with IEC 61850

In recent years, fully digital substation systems complying with the IEC 61850 standard at the station bus and process bus levels have been applied worldwide. Discussion of the application and practical use as well as development of process bus-based systems have been progressing in Japan. Tokyo Electric Power Co. Power Grid has applied its first process bus-based system at the Chiba Inzai 275kV substation. The IEC 61850 standard is applied in Process Interface Units (PIUs) and process level communication is digitalized with Intelligent Electronic Devices (IEDs). We evaluated and took measures using a failure mode and effect analysis (FMEA) method to ensure system reliability. We also considered environmental withstand in terms of impulse voltage which would affect PIUs installed closed to the switchgear. Satisfactory tests results were obtained through type test of each requirement.